This invention relates to electric control and monitoring circuits, and more specifically, to systems for measuring the alternating current drawn by loads in household and high voltage mains. The use of current transformers enables the most popular, safe and easy method of measuring the AC current drawn by loads in household and high voltage mains. Current transformers provide isolation used to isolate and scale down high voltage main current to 0-5 amps (typical) to measure the current on the primary and the output to drive analog meters. If electronic instruments are used, they must be externally powered, which increases the complexity and cost and decreases the reliability of the measurements obtained.
Currently, current transformers coupled with 4-20 mA transmitters require external power sources (compliance) for the current loop transmitter (24 VDC typically) to operate.
It is desirable to provide a current to voltage transmitter system which overcomes the disadvantages of the systems of the prior art, and which is driven by the EMF in the secondary winding of the current transformer without requiring additional internal or external power sources to energize the electronic circuitry.